일반물리학 1 — Potential Energy and Conservation of Energy: Problem 43

43 In Fig. 8-39, a 3.5 kg block is accelerated from rest by a compressed spring of spring constant 640 N/m. The block leaves the spring at the spring’s relaxed length and then travels over a horizontal floor with a coefficient of kinetic friction \(\mu_k = 0.25\). The frictional force stops the block in distance \(D = 7.8\) m. What are (a) the increase in the thermal energy of the block–floor system, (b) the maximum kinetic energy of the block, and (c) the original compression distance of the spring?